SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfff9980a43cf248146a3f28a35e91d8061a71e410ab619cbc91405654dd48dd' 
  AND token = 'lJIuaSdpnCiPZfx7+wTThw3XPClw4eWHDNAYJ0u5jNI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}